What Supplements Should You Actually Take?
Learn how to choose the right supplements using biomarkers, and avoid common mistakes driven by trends and guesswork.
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Every year, millions of people start taking supplements with one simple goal: to improve their health.
Magnesium for sleep.
Omega-3 for the heart.
Creatine for performance.
Collagen for joints.
Hair supplements for stronger hair.
But there is a fundamental question most people never ask:
Do you actually need them?
Because when it comes to supplementation, the real problem is not only doing nothing.
Sometimes the problem is doing the wrong thing.
The Rise of Supplements
Supplements have become part of daily life for many people.
In Spain alone, more than half of the population (58%) reports taking at least one dietary supplement, according to the Organización de Consumidores y Usuarios (OCU).
The reasons vary:
Improving overall health
Boosting energy
Supporting exercise performance
Improving skin, hair, or digestion
The global supplement industry is now worth hundreds of billions of euros, and continues to grow every year.
But popularity does not always equal precision.
Most supplementation decisions are not based on personal biological data.
They are based on trends, marketing, or recommendations on social media.
The Problem With Supplement Trends
Many supplements can be beneficial.
The problem is context.
The same symptom can have completely different biological causes.
For example:
Symptom | Possible Cause |
|---|---|
Fatigue | Iron deficiency |
Fatigue | Low vitamin B12 |
Fatigue | Thyroid dysfunction |
Fatigue | Chronic inflammation |
Or:
Symptom | Possible Cause |
|---|---|
Hair loss | Low ferritin |
Hair loss | Hormonal imbalance |
Hair loss | Stress |
Hair loss | Nutrient deficiency |
Without proper testing, it is easy to misinterpret the signal.
Someone experiencing fatigue might start taking magnesium.
But if the real issue is low ferritin or vitamin B12, magnesium will not solve the problem.
In fact, ferritin levels below ~30 ng/mL can already impact energy and performance, even if still considered “normal” in many labs.
When Supplementation Becomes Excess
There is another side to the problem: over-supplementation.
Taking nutrients your body already has enough of can also be harmful.
Examples include:
Excess vitamin D accumulation
Very high vitamin B12 levels
Imbalanced zinc or iron supplementation
High doses of fat-soluble vitamins
The European Food Safety Authority (EFSA) publishes upper safety limits for many nutrients for this reason.
More is not always better.
What matters is what your body actually needs.
How to Know If You’re Supplementing Blindly
You might be taking the wrong supplements if:
You take multiple supplements without testing
You started supplementing based on social media or recommendations
You still feel tired, unfocused, or low-energy despite “doing everything right”
You’ve never checked your vitamin or mineral levels
If that sounds familiar, you’re not alone.
Most people are trying to fix symptoms — without understanding the cause.
The Role of Biomarkers
This is where blood biomarkers become essential.
Instead of guessing, a biomarker analysis allows you to understand how your body is functioning internally.
Key biomarkers related to supplementation include:
Iron & Ferritin
Low ferritin is one of the most common causes of fatigue, hair loss, and reduced exercise performance.
Vitamin B12
Essential for energy metabolism, neurological function, and red blood cell production.
Vitamin D
Crucial for immune health, bone metabolism, and hormonal balance.
Up to a large part of the population shows suboptimal levels, especially in low sun exposure periods.
Magnesium
Important for muscle function, sleep regulation, and nervous system stability.
Zinc
Supports immune health, hormone production, and hair growth.
But looking at one marker alone rarely tells the full story.
Health is a system, and biomarkers interact with each other.
For example:
Iron metabolism depends on inflammation levels
Vitamin D interacts with calcium metabolism
Hormones influence nutrient utilization
This is why interpretation matters as much as measurement.
First Data. Then Decisions.
Instead of guessing what your body might need, the smarter approach is simple:
Measure your biomarkers
Identify real deficiencies
Supplement only where necessary
This transforms supplementation from a trend-driven habit into a data-driven strategy.
The goal is not to take more supplements.
The goal is to take the right ones, for the right reasons.
How Holo Helps You Understand What Your Body Needs
Most people don’t need more supplements.
They need better information.
At Holo, we analyze more than 110 biomarkers to give you a complete view of your health.
Your results include:
Advanced blood biomarkers
Integration with wearable health data
A personalized medical report
Clear recommendations and action plans
So you can stop guessing — and start making decisions based on real data.
Check your biomarkers and understand exactly what your body needs
Because better decisions start with better information.
First data. Then decisions.
References
Organización de Consumidores y Usuarios (OCU). “Más de la mitad de los españoles toma algún complemento alimenticio.” España, 2025.
Asociación Española de Complementos Alimenticios (AFEPADI). Datos de consumo de complementos alimenticios en España (informes 2023–2025).
European Food Safety Authority (EFSA). “Food Supplements.” Updated guidance on safety limits and health claims, 2026.
Observatorio de Complementos Alimenticios – Estudio Ipsos sobre hábitos de consumo de complementos alimenticios en España.
